JP5538534B2 - Method for producing fluorine-containing imide compound - Google Patents

Description

The present invention relates to an improvement in a method for producing a fluorine-containing imide compound.
This application claims priority on May 26, 2010 based on Japanese Patent Application No. 2010-120657 for which it applied to Japan, and uses the content for it here.

  It is known that a fluorinated imide compound (fluorine-containing imide compound) is a substance useful as an anion source of an ion conductive material or an ionic liquid. In addition, the ionic liquid is particularly useful as an electrolyte, reaction solvent, catalyst or the like for batteries or capacitors. This ionic liquid can be obtained, for example, by subjecting a salt of a fluorinated sulfonylimide acid, which is a fluorinated imide compound, to a salt exchange of a quaternary amine halide salt such as an imidazolium bromide salt. Generally known.

As a manufacturing method of a fluorine-containing imide compound, the method described in the nonpatent literature 1 and patent documents 1-3 is known. Specifically, in Non-Patent Document 1, as shown in the following formula (A), fluorosulfonic acid (FSO ₃ H) and urea ((NH ₂ ) ₂ CO) were reacted and produced while heating. A method for recovering bis (fluorosulfonyl) imide (FSO ₂ ) ₂ NH) and excess fluorosulfonic acid by distillation under reduced pressure is disclosed.

Patent Document 1 discloses that perfluoroalkylsulfonamide (RfSO ₂ NH ₂ , Rf is a perfluoroalkyl group) is a salt such as Na, K, Li and the like, which is disulfuryl fluoride ((FSO ₂ ) ₂ O) or A method of reacting with a halogenated sulfuryl fluoride (SO ₂ FX, X is a halogen atom) is disclosed.

Further, in Patent Document 2, as shown in the following formula (B), perfluoroalkylsulfonamide (Rf ^a SO ₂ NH ₂ ), perfluoroalkyl sulfonyl halide (Rf ^b SO ₂ X), potassium fluoride, etc. A method for producing a perfluoroalkylsulfonylimide salt ((Rf ^a SO ₂ ) (Rf ^b SO ₂ ) N · M) by reacting a fluorine compound (MF) with an organic solvent such as acetonitrile is disclosed. .

上記式（Ｂ）において、Ｒｆ^ａ及びＲｆ^ｂはペルフルオロアルキル基等を、Ｍはアルカリ金属等を、Ｘはフッ素又は塩素をそれぞれ示している。

In the above formula (B), Rf ^a and Rf ^b represent a perfluoroalkyl group, M represents an alkali metal, and X represents fluorine or chlorine.

In Patent Document 3, as shown in the following formula (C), a perfluoroalkylsulfonamide and a perfluoroalkylsulfonyl halide are reacted in the presence of a tertiary amine or a heterocyclic amine (NR ¹ R ² R ³ ). And a method for producing a perfluoroalkylsulfonylimide salt ((Rf ^c SO ₂ ) (Rf ^d SO ₂ ) N · R ¹ R ² R ³ NH) is disclosed.

上記式（Ｃ）において、Ｒｆ^ｃ及びＲｆ^ｄはペルフルオロアルキル基等を、Ｒ^１〜Ｒ^３はアルキル基等をそれぞれ示している。

In the above formula (C), Rf ^c and Rf ^d represent a perfluoroalkyl group or the like, and R ^{1 to} R ³ represent an alkyl group or the like.

JP 2005-200399 A JP 2001-288193 A JP-A-8-81436

Chem. Ber. , 95, 246-8, 1962, Appel, Eisenhauer.

  However, the method described in Non-Patent Document 1 has a problem that the reaction between urea and fluorosulfonic acid is a reaction accompanied by generation of carbon dioxide gas and a large exotherm, and the reaction proceeds runaway. It was. For this reason, the method described in Non-Patent Document 1 is difficult to control the reaction and is difficult to implement industrially.

  Further, in the method described in Patent Document 1, there is a problem that disulfuryl fluoride as a raw material is difficult to obtain and is very difficult to handle because it reacts violently with water. Further, since sulfuryl fluoride is also a gas at room temperature, there is a problem that a special apparatus such as an autoclave is required for the reaction.

Further, in the methods described in Patent Documents 2 and 3, an expensive alkali metal is used as an additive for the imidation reaction when a perfluoroalkylsulfonamide is reacted with a perfluoroalkylsulfonyl halide to produce a perfluoroalkylsulfonylimide salt. There was a problem that it was necessary to add a large amount of fluoride or tertiary amine.
Furthermore, when the carbon number of Rf is 1 or 2, the perfluoroalkylsulfonyl halide used as a raw material has a low boiling point, so that there is a problem that a special reaction apparatus such as an autoclave is required for synthesis.

  In addition, the reaction of perfluoroalkylsulfonamide and perfluoroalkylsulfonic acid anhydride, or perfluoroalkylsulfonamide and perfluoroalkylsulfonyl halide is known as a synthesis method of perfluoroalkylsulfonimide using perfluoroalkylsulfonamide so far. Yes. However, a method for synthesizing a fluorine-containing sulfonimide from fluorine-containing sulfonamide and fluorine-containing sulfonic acid is not known because the reactivity of fluorine-containing sulfonic acid is low.

  This invention is made | formed in view of the said subject, Comprising: It aims at providing the manufacturing method of a fluorine-containing imide compound with high safety | security and high productivity using an inexpensive raw material.

In order to solve the above-mentioned problems, the present inventors have conducted intensive research. As a result, it is possible to react fluorine-containing sulfonamide and fluorine-containing sulfonic acid in the presence of thionyl chloride (SOCl ₂ ). As a result, the present invention was completed.

That is, the present invention employs the following configuration.
[1] A method for producing a fluorine-containing imide compound represented by the following formula (1),
A method for producing a fluorine-containing imide compound comprising reacting a fluorine-containing sulfonic acid represented by the following formula (2) with a fluorine-containing sulfonamide represented by the following formula (3) in the presence of thionyl chloride: .
(Rf ¹ SO ₂ ) (Rf ² SO ₂ ) NH (1)
Rf ¹ SO ₃ H (2)
Rf ² SO ₂ NH ₂ (3)
However, the above formula (1) in ~ (3), Rf ¹ and Rf ² are fluorine or a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms.

[2] The fluorine-containing imide compound represented by the above formula (1) is trifluoro-N- (fluorosulfonyl) methanesulfonylamide represented by the following formula (4):
The fluorine-containing sulfonic acid represented by the above formula (2) is a fluorosulfonic acid represented by the following formula (5),
The method for producing a fluorine-containing imide compound according to item [1], wherein the fluorine-containing sulfonamide represented by the formula (3) is a trifluoromethylsulfonamide represented by the following formula (6).
(FSO ₂ ) (CF ₃ SO ₂ ) NH (4)
FSO ₃ H (5)
CF ₃ SO ₂ NH ₂ (6)

[3] A step of dissolving the thionyl chloride in the fluorine-containing sulfonic acid to form a solution,
The method for producing a fluorine-containing imide compound according to item [1] or item [2], further comprising: heating the solution, and adding the fluorine-containing sulfonamide to the reaction.
[4] A process of producing a solution by dissolving the fluorine-containing sulfonamide in the fluorine-containing sulfonic acid;
The method for producing a fluorine-containing imide compound according to [1] or [2], wherein the solution is heated, and the thionyl chloride is dropped to react with the solution.
[5] A step of mixing the fluorine-containing sulfonic acid, the fluorine-containing sulfonamide, and the thionyl chloride to form a mixed solution;
The method for producing a fluorine-containing imide compound according to [1] or [2], wherein the mixed solution is heated and reacted.

[6] The method for producing a fluorine-containing imide compound according to any one of [1] to [5], wherein the reaction temperature is in a range of 50 to 140 ° C.

  According to the method for producing a fluorine-containing imide compound of the present invention, a fluorine-containing imide is obtained from fluorine-containing sulfonic acid and fluorine-containing sulfonamide by reacting fluorine-containing sulfonic acid and fluorine-containing sulfonamide in the presence of thionyl chloride. It becomes possible to synthesize compounds. Therefore, the manufacturing method of a fluorine-containing imide compound with a high yield can be provided using the industrially easily available and easy-to-handle raw material.

Hereinafter, the manufacturing method of the fluorine-containing imide compound of this invention is demonstrated in detail.
The manufacturing method of the fluorine-containing imide compound of this embodiment is a manufacturing method of the fluorine-containing imide compound shown by following formula (7), Comprising: The fluorine-containing sulfonic acid shown by following formula (8), and following formula (9) And a fluorine-containing sulfonamide represented by ( ₂ ) in the presence of thionyl chloride (SOCl ₂ ).
(Rf ¹ SO ₂ ) (Rf ² SO ₂ ) NH (7)
Rf ¹ SO ₃ H (8)
Rf ² SO ₂ NH ₂ (9)
However, in the above formula (7) ~ (9), Rf 1 and Rf ² are fluorine or a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms.

The reaction mechanism of this embodiment is that a fluorine-containing sulfonic acid represented by the above formula (8) and a fluorine-containing sulfonamide represented by the above formula (9) are thionyl chloride by a chemical reaction represented by the following formula (10). By reacting in the presence of (SOCl ₂ ), it is presumed that a fluorine-containing imide compound represented by the above formula (7), hydrogen chloride (HCl), and sulfur dioxide (SO ₂ ) are generated.
As an advantage of the present embodiment, since by-product hydrogen chloride and sulfur dioxide are gases, they do not remain in the reaction system.

但し、上記式（１０）において、Ｒｆ^１及びＲｆ^２はフッ素又は炭素数１〜４の直鎖状あるいは分岐状のペルフルオロアルキル基である。

However, in the above formula (10), Rf ¹ and Rf ² are fluorine or a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms.

(Fluorine-containing sulfonic acid)
In the method for producing a fluorine-containing imide compound of the present embodiment, the fluorine-containing sulfonic acid represented by the above formula (8) as one raw material is fluorosulfonic acid (FSO ₃ H) and perfluoroalkylsulfonic acid. , trifluoromethylsulfonate _(CF 3 _SO 3 H), pentafluoroethyl-sulfonic acid _{(C 2 F 5 SO 3 H} ), heptafluoropropyl acid _{(C 3 F 7 SO 3 H} ), and nonafluorobutyl sulfonic acid (C ₄ F ₉ SO ₃ H). In the method for producing a fluorine-containing imide compound of the present embodiment, among these fluorine-containing sulfonic acids, when fluorosulfonic acid is used, production of perfluoro-N- (fluorosulfonyl) alkanesulfonylamide, which has been difficult in the past, is performed. It becomes possible and preferable.

(Fluorine-containing sulfonamide)
In addition, examples of the fluorine-containing sulfonamide represented by the above formula (9) as the other raw material include fluorosulfonamide (FSO ₂ NH ₂ ) and perfluoroalkylsulfonamide, trifluoromethylsulfonamide (CF ₃ SO ₂ NH _2), pentafluoroethyl sulfonamide _{(C 2 F 5 SO 2 NH} 2), heptafluoropropyl sulfonamide _{(C 3 F 7 SO 2 NH} 2), and nonafluorobutyl sulfonamide _{(C 4} F 9 SO ₂ NH ₂₎ can be mentioned. In the method for producing a fluorine-containing imide compound of this embodiment, among these fluorine-containing sulfonamides, trifluoromethylsulfonamide, pentafluoroethylsulfonamide, heptafluoropropylsulfonamide, nonafluorobutylsulfonamide, or the like is used. Is more preferable from the viewpoint of easy availability of raw materials, and the use of trifluoromethylsulfonamide is most preferable from the viewpoint of easy availability of raw materials.

(Fluorine-containing imide)
The method for producing a fluorine-containing imide compound according to this embodiment is particularly effective for the synthesis of an asymmetric fluorine-containing imide compound in which either one of Rf ¹ and Rf ² is fluorine, which has conventionally been difficult to produce.

In the fluorine-containing imide compound represented by the above formula (7), when Rf ¹ and Rf ² are the same (symmetric structure), bis (fluorosulfonyl) imide [(FSO ₂ ) ₂ NH], bis (trifluoromethane) Sulfonyl) imide [(CF ₃ SO ₂ ) ₂ NH], bis (pentafluoroethanesulfonyl) imide [(C ₂ F ₅ SO ₂ ) ₂ NH], bis (heptafluoropropanesulfonyl) imide [(C ₃ F ₇ SO ₂ ) ₂ NH] and perfluoroalkylsulfonimides such as bis (nonafluorobutanesulfonyl) imide [(C ₄ F ₉ SO ₂ ) ₂ NH]. In Rf ¹ and Rf ² of the present embodiment, when the number of carbon atoms is 3 or 4, branched structural isomers are included in addition to the straight chain (hereinafter, the same applies when the number of carbon atoms is 3 or 4). ).

When Rf ¹ and Rf ² are different (asymmetric structure), as the fluorine-containing imide compound, trifluoro-N- (fluorosulfonyl) methanesulfonylamide [(FSO ₂ ) (CF ₃ SO ₂ ) NH], pentafluoro -N- (fluorosulfonyl) ethane sulfonyl amide _{[(FSO 2) (C 2} F 5 SO 2) NH], heptafluoro -N- (fluorosulfonyl) propane sulfonyl amide _{[(FSO 2) (C 3} F 7 SO 2 ) NH], nonafluoro-N- (fluorosulfonyl) butanesulfonylamide [(FSO ₂ ) (C ₄ F ₉ SO ₂ ) NH], pentafluoro-N-[(trifluoromethane) sulfonyl] ethanesulfonylamide [(CF _{3 SO 2) (C 2 F 5} SO 2) NH], heptafluoro -N - [( Trifluoromethane) sulfonyl] propane sulfonyl amide _{[(CF 3 SO 2) (} C 3 F 7 SO 2) NH], nonafluoro -N - [(trifluoromethane) sulfonyl] butane sulfonyl amide _{[(CF 3 SO 2) (} C _{4 F 9 SO 2) NH]} , heptafluoro -N - [(pentafluoroethane) sulfonyl] propane sulfonyl amide _{[(C 2 F 5 SO 2} ) (C 3 F 7 SO 2) NH], nonafluoro -N- [ (pentafluoroethane) sulfonyl] butane sulfonyl amide _{[(C 2 F 5 SO 2} ) (C 4 F 9 SO 2) NH], nonafluoro -N - [(heptafluoropropane) sulfonyl] butane sulfonyl amide _[(C 3 F ₇ SO ₂ ) (C ₄ F ₉ SO ₂ ) NH] and the like.

When producing an asymmetric fluorine-containing imide compound in which either Rf ¹ or Rf ² is fluorine in the conventional method for producing a fluorine-containing imide compound, it is difficult to produce as compared with the case of producing other fluorine-containing imide compounds. Met. The method for synthesizing a fluorine-containing imide compound according to this embodiment is effective for synthesizing an asymmetric fluorine-containing imide compound in which either Rf ¹ or Rf ² is fluorine.
In the method for producing a fluorine-containing imide compound of the present embodiment, it is possible to synthesize trifluoro-N- (fluorosulfonyl) methanesulfonylamide among the asymmetric fluorine-containing imide compounds from the viewpoint of easy availability of raw materials. More preferred.

In the method for producing a fluorine-containing imide compound of the present embodiment, fluorosulfonic acid (FSO ₃ H) is used as the fluorine-containing sulfonic acid represented by the above formula (8), and trifluoride is used as the fluorine-containing sulfonamide represented by the above formula (9). Trifluoro- which is an asymmetric fluorine-containing imide compound in which Rf ¹ and Rf ² are different from each other as a fluorine-containing imide compound represented by the above formula (7) using each of fluoromethylsulfonamide (CF ₃ SO ₂ NH ₂ ). It is particularly preferable to apply it when synthesizing N- (fluorosulfonyl) methanesulfonylamide [(FSO ₂ ) (CF ₃ SO ₂ ) NH].

  The first method in the method for producing a fluorine-containing imide compound of the present embodiment is a process of dissolving thionyl chloride in fluorine-containing sulfonic acid to form a solution (solution formation process), and heating the solution. This is a method for producing a fluorine-containing imide compound comprising a process of adding a fluorine-containing sulfonamide and reacting it (addition reaction process). Each process will be specifically described below.

(Solution generation process)
First, the fluorine-containing sulfonic acid and thionyl chloride are charged into the reaction vessel without reacting to produce a solution in which thionyl chloride is dissolved in the fluorine-containing sulfonic acid.

  Here, the amount of the fluorine-containing sulfonic acid is preferably 1 to 20 times, more preferably 1 to 8 times in terms of molar ratio with respect to the fluorine-containing sulfonamide to be added. When the molar ratio of the fluorine-containing sulfonic acid is less than 1 times the fluorine-containing sulfonamide, the fluorine-containing sulfonic acid necessary for the reaction is insufficient and the production amount of the fluorine-containing imide compound is decreased, which is not preferable. . On the other hand, when the amount of the fluorine-containing sulfonic acid exceeds 20 times in molar ratio with respect to the fluorine-containing sulfonamide to be added, it is economically useless.

  In addition, the amount of thionyl chloride is preferably 1 to 10 times, more preferably 1 to 5 times in terms of molar ratio with respect to the fluorine-containing sulfonamide to be added. When the molar ratio is less than 1 time with respect to the fluorine-containing sulfonamide added by thionyl chloride, the amount of thionyl chloride necessary for the reaction is insufficient and the production amount of the fluorine-containing imide compound is lowered, which is not preferable. On the other hand, if the amount of thionyl chloride exceeds 10 times in molar ratio with respect to the fluorine-containing sulfonamide to be added, it is economically wasteful.

  In this embodiment, it is considered that the reactivity is increased by reacting the fluorine-containing sulfonic acid and the fluorine-containing sulfonamide in the presence of thionyl chloride.

(Addition reaction process)
In the addition reaction process, first, the dissolving solution charged in the reaction vessel is heated. Next, fluorine-containing sulfonamide is added to the heating reaction vessel. In this way, the fluorine-containing sulfonic acid and the fluorine-containing sulfonamide are reacted in the presence of thionyl chloride.

  Here, the reaction temperature in the reaction vessel during addition of the fluorine-containing sulfonamide is preferably in the range of 50 to 140 ° C, more preferably in the range of 60 to 120 ° C. A reaction temperature of less than 50 ° C. is not preferable because the reaction progresses slowly. On the other hand, if it exceeds 140 ° C., thionyl chloride volatilizes, which is not preferable. Therefore, it is preferable that the temperature of the solution of fluorine-containing sulfonic acid and thionyl chloride to be heated in advance is, for example, 60 to 120 ° C.

  The second method in the method for producing a fluorine-containing imide compound of the present embodiment includes a process of dissolving a fluorine-containing sulfonamide in fluorine-containing sulfonic acid to form a solution (solution generation process), and this solution And a step of dripping thionyl chloride to react with this (a dropping reaction step), and a method for producing a fluorine-containing imide compound.

  Here, the second method is different from the first method described above in that thionyl chloride dissolved in the fluorine-containing sulfonic acid and the fluorine-containing sulfonamide to be added are exchanged. About the reaction temperature in a container, it is the same conditions as a 1st method.

  Further, the third method in the present embodiment includes a process of mixing a fluorine-containing sulfonic acid, a fluorine-containing sulfonamide, and thionyl chloride to form a mixed liquid (a mixed liquid generation process), and this mixed liquid. And a process of heating and reacting (heating reaction process), and a method for producing a fluorine-containing imide compound.

  Here, the third method is the same as the first and second methods described above, in which thionyl chloride and fluorine-containing sulfonamide are dissolved in advance in fluorine-containing sulfonic acid and then heated. The amount and the reaction temperature in the reaction vessel are the same conditions as in the first method.

  As described above, according to the method for producing a fluorine-containing imide compound of the present embodiment, fluorine-containing sulfonic acid and fluorine-containing sulfonamide are reacted with each other in the presence of thionyl chloride. It becomes possible to synthesize a fluorine-containing imide compound from a sulfonamide. Therefore, the manufacturing method of a fluorine-containing imide compound with a high yield can be provided using the industrially easily available and easy-to-handle raw material.

  In addition, according to the method for producing a fluorine-containing imide compound of the present embodiment, a fluorine-containing sulfonimide having a symmetric structure and an asymmetric structure is easily produced by reacting a fluorine-containing sulfonic acid and a fluorine-containing sulfonamide in combination. be able to.

  Moreover, according to the manufacturing method of the fluorine-containing imide compound of this embodiment, it is thought that the reactivity can be improved by adding thionyl chloride to the reaction system. Thereby, the method of synthesize | combining a fluorine-containing imide compound from the fluorine-containing sulfonamide and fluorine-containing sulfonic acid which were not known conventionally can be provided.

  In addition, according to the method for producing a fluorine-containing imide compound of the present embodiment, since the boiling point of fluorine-containing sulfonic acid, which is one of the raw materials, is high, the fluorine-containing imide compound can be easily obtained without using a special device such as an autoclave. Can be manufactured.

  Moreover, according to the manufacturing method of the fluorine-containing imide compound of this embodiment, the synthesis | combination of the fluorine-containing imide compound used for a battery electrolyte etc. from a sulfonamide and a sulfonic acid is attained.

  Hereinafter, the effects of the present invention will be described in more detail by way of examples. In addition, this invention is not limited at all by the Example.

Example 1
A 100 mL glass reactor equipped with a stirrer and a thermometer was charged with 30 g of trifluoromethylsulfonamide, 46 g of thionyl chloride, and 88 g of fluorosulfonic acid, and reacted at 120 ° C. for 12 hours. During the reaction, generation of hydrogen chloride gas and sulfur dioxide gas was confirmed.
The reaction solution was added dropwise to water and analyzed by ¹⁹ F-NMR. The peaks of trifluoro-N- (fluorosulfonyl) methanesulfonylamide were confirmed at 56.7 ppm and -78.3 ppm, respectively.
The yield based on trifluoromethylsulfonamide of trifluoro-N- (fluorosulfonyl) methanesulfonylamide was 70% by the internal standard addition method.

(Example 2)
A 100 mL glass reactor equipped with a stirrer and a thermometer was charged with 50 g of fluorosulfonic acid and 15 g of trifluoromethylsulfonamide, and heated to 120 ° C. 24 g of thionyl chloride was added dropwise to the heated reaction solution over 2 hours. During the dropping, generation of hydrogen chloride gas and sulfur dioxide gas was confirmed.
After completion of dropping, the reaction was performed at 120 ° C. for 2 hours. After completion of the reaction, the reaction solution was added dropwise to water and analyzed by ¹⁹ F-NMR. The peaks of trifluoro-N- (fluorosulfonyl) methanesulfonylamide were confirmed at 56.7 ppm and -78.3 ppm, respectively.
According to the internal standard addition method, the yield of trifluoro-N- (fluorosulfonyl) methanesulfonylamide based on trifluoromethylsulfonamide was 81%.

(Comparative Example 1)
In a 100 mL glass reactor equipped with the same apparatus stirrer and thermometer as in Example 1, 45 g of fluorosulfuric acid was charged and heated at 80 ° C. 22 g of trifluoromethylsulfonamide was added and further reacted at 80 ° C. for 130 hours.
The reaction solution was added dropwise to water and analyzed by ¹⁹ F-NMR. No trifluoro-N- (fluorosulfonyl) methanesulfonylamide peak was detected.

  In the method for producing a fluorine-containing imide compound shown in the present embodiment, a fluorine-containing imide compound can be produced using fluorine-containing sulfonic acid, fluorine-containing sulfonamide, and thionyl chloride that are industrially easily available. The imide compound can be industrially useful as an ion conductive material or an anion source of an ionic liquid.

Claims (6)

A method for producing a fluorine-containing imide compound represented by the following formula (1):
A method for producing a fluorine-containing imide compound comprising reacting a fluorine-containing sulfonic acid represented by the following formula (2) with a fluorine-containing sulfonamide represented by the following formula (3) in the presence of thionyl chloride: .
(Rf ¹ SO ₂ ) (Rf ² SO ₂ ) NH (1)
Rf ¹ SO ₃ H (2)
Rf ² SO ₂ NH ₂ (3)
However, the above formula (1) in ~ (3), Rf ¹ and Rf ² are fluorine or a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms. The fluorine-containing imide compound represented by the above formula (1) is trifluoro-N- (fluorosulfonyl) methanesulfonylamide represented by the following formula (4),
The fluorine-containing sulfonic acid represented by the above formula (2) is a fluorosulfonic acid represented by the following formula (5),
The method for producing a fluorine-containing imide compound according to claim 1, wherein the fluorine-containing sulfonamide represented by the formula (3) is a trifluoromethylsulfonamide represented by the following formula (6).
(FSO ₂ ) (CF ₃ SO ₂ ) NH (4)
FSO ₃ H (5)
CF ₃ SO ₂ NH ₂ (6) Dissolving the thionyl chloride in the fluorine-containing sulfonic acid to form a solution;
The method for producing a fluorine-containing imide compound according to claim 1, further comprising a step of heating the solution and adding the fluorine-containing sulfonamide to the reaction. Dissolving the fluorine-containing sulfonamide in the fluorine-containing sulfonic acid to produce a solution;
The method for producing a fluorine-containing imide compound according to claim 1, further comprising a step of heating the solution and dropping the thionyl chloride to react with the solution. A step of mixing the fluorine-containing sulfonic acid, the fluorine-containing sulfonamide, and the thionyl chloride to form a mixed solution;
The method for producing a fluorine-containing imide compound according to claim 1, further comprising a step of reacting the mixed liquid by heating.   The method for producing a fluorine-containing imide compound according to any one of claims 1 to 5, wherein the reaction temperature is in the range of 50 to 140 ° C.